Symbols in electricity. Letter designations of elements on electrical diagrams
To understand what is specifically drawn on a diagram or drawing, you need to know the decoding of those icons that are on it. This recognition is also called drawing reading. And to facilitate this lesson, almost all elements have their own conventional icons. Almost, because the standards have not been updated for a long time and some elements are drawn by everyone as best they can. But, for the most part, the conventions in electrical circuits ah is in the regulatory documents.
Symbols in electrical circuits: lamps, transformers, measuring instruments, main element base
Normative base
There are about a dozen varieties of electrical circuits, the number of different elements that can be found there is in the tens, if not hundreds. To facilitate the recognition of these elements, uniform symbols have been introduced in electrical circuits. All rules are written in GOSTs. There are a lot of these standards, but the main information is in the following standards:
Studying GOSTs is a useful thing, but it takes time, which not everyone has enough of. Therefore, in the article we present the symbols in electrical circuits - the main element base for creating drawings and wiring diagrams, circuit diagrams devices.
Some experts, having carefully looked at the circuit, can say what it is and how it works. Some may even issue possible problems that may occur during operation. It's simple - they know the circuitry and the element base well, and are also well versed in the symbols of the circuit elements. Such a skill has been developed over the years, and, for "dummies", it is important to remember the most common ones to begin with.
Electrical panels, cabinets, boxes
On the power supply diagrams of a house or apartment, there will necessarily be a designation or a cabinet. In apartments, the terminal device is mainly installed there, since the wiring does not go further. In houses, they can design the installation of a branching electrical cabinet - if a route goes from it to illuminate other buildings located at some distance from the house - a bathhouse, a guest house. These other designations are in the next picture.
If we talk about images of the "stuffing" of electrical panels, it is also standardized. There are symbols for RCDs, circuit breakers, buttons, current and voltage transformers, and some other elements. They are given following table(two pages in the table, scroll by clicking on the word "Next")
| Number | Name | Image on the diagram |
|---|---|---|
| 1 | Circuit breaker (automatic) |  |
| 2 | Knife switch (load switch) |  |
| 3 | Thermal relay (overheating protection) |  |
| 4 | RCD (residual current device) |  |
| 5 | Differential automaton (difavtomat) |  |
| 6 | Fuse | |
| 7 | Switch (knife switch) with fuse |  |
| 8 | Circuit breaker with built-in thermal relay (for motor protection) |  |
| 9 | Current transformer |  |
| 10 | voltage transformer |  |
| 11 | electricity meter |  |
| 12 | Frequency converter |  |
| 13 | Button with automatic opening of contacts after pressing |  |
| 14 | Button with contact opening when pressed again |  |
| 15 | Button with a special switch to disable (stop, for example) |  |
Element base for wiring diagrams
When drawing up or reading a diagram, the designations of wires, terminals, grounding, zero, etc. will also come in handy. This is what a novice electrician simply needs or in order to understand what is shown in the drawing and in what sequence its elements are connected.
| Number | Name | Designation of electrical elements on the diagrams |
|---|---|---|
| 1 | Phase conductor |  |
| 2 | Neutral (zero working) N |  |
| 3 | Protective conductor ("earth") PE |  |
| 4 | Combined protective and neutral conductors PEN |  |
| 5 | Electric communication line, busbars |  |
| 6 | Bus (if it needs to be selected) |  |
| 7 | Busbar taps (made by soldering) |  |
An example of using the above graphic images is in the following diagram. Thanks to the letter designations, everything is clear even without graphics, but duplication of information in the diagrams has never been superfluous.
Picture of sockets
On the wiring diagram, the installation locations of sockets and switches should be marked. There are many types of sockets - for 220 V, for 380 V, hidden and open type of installation, with a different number of "seats", waterproof, etc. To give the designation of each is too long and useless. It is important to remember how the main groups are depicted, and the number of contact groups is determined by the strokes.
Designation of sockets in the drawings
Sockets for single-phase network 220 V are indicated on the diagrams in the form of a semicircle with one or more segments sticking up. The number of segments is the number of sockets on one housing (illustrated in the photo below). If only one plug can be plugged into the outlet, one segment is drawn up, if two, two, etc.
If you look at the images carefully, you will notice that the symbolic image on the right does not have horizontal bar, which separates the two parts of the icon. This feature indicates that the socket is flush-mounted, that is, it is necessary to make a hole in the wall under it, install a socket box, etc. The option on the right is for surface mounting. A non-conductive substrate is attached to the wall, and the socket itself is attached to it.
Also note that the lower part of the left schematic is crossed out. vertical line. This indicates the presence of a protective contact, to which grounding is applied. The installation of sockets with grounding is mandatory when turning on a complex household appliances type washing or, oven, etc.
You can’t confuse the symbol of a three-phase socket (for 380 V) with anything. The number of segments sticking up is equal to the number of conductors that are to this device connected - three phases, zero and earth. Total five.
It happens that the lower part of the image is painted over with black (dark). This means that the outlet is waterproof. These are placed on the street, in rooms with high humidity (baths, pools, etc.).
Switch display
The schematic designation of switches looks like a small circle with one or more L- or T-shaped branches. Branches in the form of the letter "G" designate an open-mounted switch, with the form of the letter "T" - flush-mounted. The number of taps displays the number of keys on this device.
In addition to the usual ones, they can stand - to be able to turn on / off one light source from several points. Two letters "G" are added to the same small circle from opposite sides. This is the designation of a single-key pass-through switch.
Unlike conventional switches, in these, when using two-button models, one more bar is added parallel to the top one.
Lamps and fixtures
Lamps have their own designations. And the lamps are different. daylight(fluorescent) and incandescent lamps. The diagrams even show the shape and size of the fixtures. In this case, you just need to remember how each type of lamp looks on the diagram.
Radioelements
When reading circuit diagrams of devices, you need to know the symbols for diodes, resistors, and other similar elements.
Knowing the conditional graphic elements will help you read almost any diagram - some kind of device or electrical wiring. The ratings of the required parts are sometimes affixed next to the image, but in large multi-element circuits they are written in a separate table. It contains the letter designations of the circuit elements and the denominations.
Letter designations
In addition to the fact that the elements on the diagrams have conditional graphic names, they have letter designations, which are also standardized (GOST 7624-55).
| Name of electrical circuit element | Letter designation | |
|---|---|---|
| 1 | Switch, controller, switch | AT |
| 2 | Electric generator | G |
| 3 | Diode | D |
| 4 | Rectifier | Vp |
| 5 | Sound alarm (bell, siren) | Sv |
| 6 | Button | Kn |
| 7 | incandescent lamp | L |
| 8 | Electrical engine | M |
| 9 | Fuse | Etc |
| 10 | Contactor, magnetic starter | To |
| 11 | Relay | R |
| 12 | Transformer (autotransformer) | Tr |
| 13 | plug connector | W |
| 14 | Electromagnet | Em |
| 15 | Resistor | R |
| 16 | Capacitor | FROM |
| 17 | Inductor | L |
| 18 | Control button | Ku |
| 19 | Terminal switch | Kv |
| 20 | Throttle | dr |
| 21 | Telephone | T |
| 22 | Microphone | Mk |
| 23 | Speaker | Gr |
| 24 | Battery (galvanic cell) | B |
| 25 | Main engine | Dg |
| 26 | Cooling pump motor | Before |
Please note that in most cases Russian letters are used, but the resistor, capacitor and inductor are indicated in Latin letters.
There is one subtlety in the designation of the relay. They are different type, respectively marked:
- current relay - RT;
- power - RM;
- voltage - PH;
- time - RV;
- resistance - RS;
- index - RU;
- intermediate - RP;
- gas - RG;
- with time delay - RTV.
Basically, these are only the most conventional symbols in electrical circuits. But most of the drawings and plans you can now understand. If you need to know images of rarer elements, study GOSTs.
In this article, we will consider the designation of radio elements in the diagrams.
Where to start reading diagrams?
In order to learn how to read circuits, first of all, we must study how this or that radio element looks in the circuit. In principle, there is nothing complicated about this. The whole point is that if there are 33 letters in the Russian alphabet, then in order to learn the designations of radio elements, you will have to try hard.
Until now, the whole world cannot agree on how to designate this or that radio element or device. Therefore, keep this in mind when you collect bourgeois schemes. In our article, we will consider our Russian GOST version of the designation of radioelements
Learning a simple circuit
Okay, more to the point. Let's look at a simple electrical circuit of the power supply, which used to flash in any Soviet paper publication:
If you have been holding a soldering iron in your hands for more than a day, then everything will immediately become clear to you at a glance. But among my readers there are those who are faced with such drawings for the first time. Therefore, this article is mainly for them.
Well, let's analyze it.
Basically, all diagrams are read from left to right, just like you read a book. Any different scheme can be represented as a separate block, to which we supply something and from which we remove something. Here we have a power supply circuit, to which we supply 220 volts from the outlet of your house, and a constant voltage comes out from our block. That is, you must understand what is the main function of your circuit. You can read it in the description for it.
How radio elements are connected in a circuit
So, it seems that we have decided on the task of this scheme. Straight lines are wires, or printed conductors, along which electric current will run. Their task is to connect radio elements.
The point where three or more conductors join is called node. We can say that in this place the wiring is soldered:
If you look closely at the circuit, you can see the intersection of two conductors
Such an intersection will often flash in the diagrams. Remember once and for all: at this point the wires do not connect and they must be isolated from each other. AT modern schemes most often you can see this option, which already visually shows that there is no connection between them:
Here, as it were, one wire goes around the other from above, and they do not contact each other in any way.
If there was a connection between them, then we would see this picture:
The letter designation of radio elements in the scheme
Let's take a look at our diagram again.
As you can see, the scheme consists of some obscure icons. Let's take a look at one of them. Let it be the R2 icon.
So, let's deal with the inscriptions first. R means . Since he is not the only one in our scheme, the developer of this scheme gave him the serial number “2”. There are 7 of them in the scheme. Radio elements are generally numbered from left to right and top to bottom. A rectangle with a dash inside already clearly shows that this is a fixed resistor with a power dissipation of 0.25 watts. Also next to it is written 10K, which means its face value is 10 Kiloom. Well, something like this...
How are the other radioelements designated?
To designate radio elements, single-letter and multi-letter codes are used. Single letter codes are Group to which the element belongs. Here are the main groups of radio elements:
BUT - this is various devices(e.g. amplifiers)
AT - converters are not electrical quantities to electrical and vice versa. This may include various microphones, piezoelectric elements, speakers, etc. Generators and power supplies here do not apply.
FROM – capacitors
D – integrated circuits and various modules
E - different elements that do not fall into any group
F – arresters, fuses, protective devices
H – indicating and signaling devices, e.g. sound and light indication devices
K – relays and starters
L – inductors and chokes
M – engines
R – instruments and measuring equipment
Q - switches and disconnectors in power circuits. That is, in circuits where a large voltage and a large current “walk”
R - resistors
S - switching devices in control, signaling and measurement circuits
T – transformers and autotransformers
U - Converters of electrical quantities into electrical, communication devices
V – semiconductor devices
W – microwave lines and elements, antennas
X - contact connections
Y – mechanical devices with electromagnetic drive
Z – terminal devices, filters, limiters
To clarify the element, after the one-letter code comes the second letter, which already means element type. Below are the main types of elements along with the group letter:
BD – ionizing radiation detector
BE – synchro-receiver
BL – photocell
BQ – piezoelectric element
BR – speed sensor
BS - pickup
BV - speed sensor
BA - loudspeaker
BB – magnetostrictive element
BK – thermal sensor
BM - microphone
BP - pressure meter
BC – synchro sensor
DA – integrated analog circuit
DD – integrated digital circuit, logic element
D.S. - information storage device
DT - delay device
EL - lighting lamp
EK - heating element
FA – instantaneous current protection element
FP – current protection element of inertial action
FU - fuse
FV – voltage protection element
GB - battery
HG – symbolic indicator
HL - light signaling device
HA - sound alarm device
KV – voltage relay
KA – current relay
KK – electrothermal relay
KM - magnetic switch
KT – time relay
PC – pulse counter
PF – frequency meter
PI – active energy meter
PR - ohmmeter
PS - recording device
PV - voltmeter
PW - wattmeter
PA - ammeter
PK – reactive energy meter
PT - watch
QF
QS - disconnector
RK – thermistor
RP - potentiometer
RS – measuring shunt
EN – varistor
SA – switch or switch
SB - push button switch
SF - Automatic switch
SK – temperature switches
SL – level switches
SP – pressure switches
SQ – position-operated switches
SR – switches triggered by rotational speed
TV – voltage transformer
TA - current transformer
UB – modulator
UI – discriminator
UR – demodulator
USD – frequency converter, inverter, frequency generator, rectifier
VD - diode, zener diode
VL - electrovacuum device
VS – thyristor
VT –
WA – antenna
wt - phase shifter
WU - attenuator
XA – current collector, sliding contact
XP - pin
XS - nest
XT - collapsible connection
XW – high frequency connector
YA – electromagnet
YB – brake with electromagnetic drive
YC – clutch with electromagnetic drive
YH – electromagnetic plate
ZQ – quartz filter
Graphic designation of radio elements in the circuit
I will try to give the most popular designations of the elements used in the diagrams:
Resistors and their types
a) general designation
b) power dissipation 0.125 W
in) power dissipation 0.25 W
G) power dissipation 0.5 W
d) power dissipation 1 W
e) power dissipation 2 W
and) power dissipation 5 W
h) power dissipation 10 W
and) power dissipation 50 W
Resistors variable
Thermistors
Strain gauges
Varistors
Shunt
Capacitors
a) the general designation of the capacitor
b) varicond
in) polar capacitor
G) trimmer capacitor
d) variable capacitor
Acoustics
a) headphone
b) loudspeaker (speaker)
in) general designation of a microphone
G) electret microphone
Diodes
a) diode bridge
b) the general designation of the diode
in) zener diode
G) double-sided zener diode
d) bidirectional diode
e) Schottky diode
and) tunnel diode
h) reversed diode
and) varicap
to) Light-emitting diode
l) photodiode
m) emitting diode in an optocoupler
n) a radiation-receiving diode in an optocoupler
Meters of electrical quantities
a) ammeter
b) voltmeter
in) voltammeter
G) ohmmeter
d) frequency meter
e) wattmeter
and) faradometer
h) oscilloscope
Inductors
a) coreless inductor
b) core inductor
in) trimmer inductor
transformers
a) the general designation of the transformer
b) transformer with output from the winding
in) current transformer
G) transformer with two secondary windings(maybe more)
d) three-phase transformer
Switching devices
a) closing
b) opening
in) opening with return (button)
G) closing with return (button)
d) switching
e) reed switch
Electromagnetic relay with different groups of contacts
Circuit breakers
a) general designation
b) the side that remains energized when the fuse blows is highlighted
in) inertial
G) fast acting
d) thermal coil
e) switch-disconnector with fuse
Thyristors
bipolar transistor
unijunction transistor
When carrying out electrical work, each person, one way or another, is faced with the symbols that are in any electrical circuit. These schemes are very diverse, with different functions, however, all graphic symbols are reduced to uniform forms and correspond to the same elements in all schemes.
The main symbols in the GOST electrical circuits are displayed in the tables
At present, not only domestic elements are used in electrical engineering and radio electronics, but also products manufactured by foreign firms. Imported electrical radio elements make up a huge assortment. They, without fail, are displayed on all drawings in the form of symbols. They determine not only the values of the main electrical parameters, but also their complete list included in a particular device, as well as the relationship between them.
To read and understand the contents of the electrical diagram
It is necessary to study well all the elements that make up its composition and the principle of operation of the device as a whole. Usually, all information is either in reference books or in the specification attached to the circuit. Positional designations characterize the relationship of the elements included in the device kit with their designations on the diagram. In order to graphically designate one or another electrical radio element, standard geometric symbols are used, where each product is depicted separately, or in combination with others. The meaning of each individual image largely depends on the combination of symbols with each other.
Each diagram shows
Connections between individual elements and conductors. In such cases, the standard designation of identical components and elements is of no small importance. For this, there are positional designations, where the types of elements, their design features and digital values are displayed in literal terms. Elements used in a general manner are indicated in the drawings as qualifying, characterizing current and voltage, control methods, types of connections, pulse shapes, electronic communication, and others.
In order to correctly read and understand what this or that diagram or drawing related to electricity means, you need to know how the icons and symbols depicted on them are deciphered. A large number of information contain letter designations of elements in electrical circuits, determined by various regulatory documents. All of them are displayed in Latin characters in the form of one or two letters.
Single-letter symbolism of elements
Letter codes corresponding to individual types of elements most widely used in electrical circuits are combined into groups designated by one character. Letter designations correspond to GOST 2.710-81. For example, the letter "A" refers to the "Devices" group, which consists of lasers, amplifiers, telecontrol devices, and others.
In the same way, the group denoted by the symbol "B" is deciphered. It consists of devices that convert non-electric quantities into electrical quantities, which do not include generators and power supplies. This group is complemented by analog or multi-digit transducers, as well as sensors for indications or measurements. The components themselves included in the group are represented by microphones, loudspeakers, sound pickups, ionizing radiation detectors, thermoelectric sensing elements, etc.
All letter designations corresponding to the most common elements are combined in a special table for ease of use:
|
The first alphabetic character required to be reflected in the marking |
Group of main types of elements and devices |
Elements that make up the group (the most typical examples) |
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Devices |
Lasers, masers, telecontrol devices, amplifiers. |
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Apparatus for converting non-electric quantities into electrical (without generators and power supplies), analog and multi-charge converters, sensors for indications or measurements |
Microphones, loudspeakers, sound pickups, ionizing radiation detectors, sensitive thermoelectric elements. |
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Capacitors |
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Microassemblies, integrated circuits |
integrated circuits digital and analog, memory and delay devices, logic elements. |
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Miscellaneous elements |
Various types of lighting devices and heating elements. |
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Designation of the fuse on the diagram, arresters, protective devices |
Fuses, arresters, discrete elements current and voltage protection. |
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Power supplies, generators, crystal oscillators |
Rechargeable batteries, power sources on an electrochemical and electrothermal basis. |
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Devices for signals and indications |
Indicators, light and sound signaling devices |
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Contactors, relays, starters |
Voltage and current relays, time relays, electrothermal relays, magnetic starters, contactors. |
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Chokes, inductors |
Chokes in fluorescent lighting. |
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Engines |
DC and AC motors. |
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Measuring instruments and equipment |
Counters, clocks, showing, recording and measuring instruments. |
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Power automatic switches, short circuiters, disconnectors. |
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Resistors |
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Pulse counters |
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Frequency meters |
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Active energy meters |
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Reactive energy meters |
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Recording devices |
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Action time meters, hours |
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Voltmeters |
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Wattmeters |
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Switches and disconnectors in power circuits |
Circuit breakers |
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Short circuiters |
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Disconnectors |
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Resistors |
Thermistors |
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Potentiometers |
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Measuring shunts |
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Varistors |
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Switching devices in measurement, control and signaling circuits |
Breakers and switches |
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Pushbutton switches |
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Automatic switches |
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Switches triggered by various factors: From level |
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From pressure |
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From position (travel) |
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From rotational speed |
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From temperature |
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Transformers, autotransformers |
Current transformers |
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Electromagnetic stabilizers |
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Voltage transformers |
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Communication devices, converters of non-electric quantities into electrical ones |
Modulators |
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Demodulators |
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Discriminators |
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Frequency generators, inverters, frequency converters |
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Semiconductor and electrovacuum devices |
Diodes, zener diodes |
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Electrovacuum devices |
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transistors |
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Thyristors |
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Antennas, lines and microwave elements |
Taps |
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Short circuiters |
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Transformers, phase shifters |
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Attenuators |
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Contact connections |
Sliding contacts, current collectors |
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Collapsible connections |
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High frequency connectors |
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Mechanical devices with electromagnetic drive |
electromagnets |
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Brakes with electromagnetic actuators |
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Couplings with electromagnetic drives |
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Electromagnetic cartridges or plates |
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Limiters, terminal devices, filters |
Limiters |
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Quartz filters |
In addition, GOST 2.710-81 defines Special symbols to identify each element.
Conventional graphic designations of electronic components in circuits
Reading electrical drawings requires certain knowledge, which can be gleaned from normative documents. A kind of "language" of reading are symbols in electrical circuits – a system of signs and symbols, mainly graphic and alphabetic. In addition to them, denominations are sometimes affixed in numbers.
Agree, understanding the standard notation is simply necessary for any home master. This knowledge will help you read the wiring diagram, independently draw up a wiring plan in an apartment or in a private house. We offer to understand all the intricacies of writing project documentation.
The article describes the main types of electrical circuits, as well as a detailed decoding of the basic images, symbols, icons and alphanumeric markers used in drawing up drawings for the electrical network device.
Consider the design information from the point of view of an amateur electrician who wants to change the wiring in the house with his own hands or draw up a drawing for connecting the dacha to electrical communications.
First you need to understand what knowledge will be useful and what will not be needed. First step – is an introduction to the species.
A shield diagram using real images of switching, protective devices - electrical connections are shown with colored wires. In fact, it has nothing to do with professional documentation that accompanies home energy projects.
All information about the types of schemes is set out in the new edition of GOST 2.702-2011, which is called "ESKD. Rules for the implementation of electrical circuits.
This is a duplicate of an earlier document – GOST 2.701-2008, which just talks in detail about the classification of schemes. In total, 10 species are distinguished, but in practice only one may be required. – electric.
In addition to the species classification, there is also a typical one, which subdivides all drawing documents into structural, general, etc., in total 8 points.
The home master will be interested in 3 types of circuits: functional, basic, assembly.
Type #1 - function diagram
The functional diagram does not contain details, it indicates the main blocks and nodes. It gives a general idea of how the system works. For a private house power supply device, it does not always make sense to draw up such drawings, since they are usually typical.
But when describing a complex electronic device or to equip a workshop, studio or control room with an electrician, they can come in handy.
